Technical Field
The present disclosure relates to a seal cap for a barrel, a syringe assembly to which the seal cap for a barrel is mounted, a prefilled syringe using the syringe assembly to which the seal cap for a barrel is mounted, and a package body storing a plurality of syringe assemblies.
Background Art
A syringe having a puncture needle fixed at a distal end of a barrel has been used as a syringe for administering a low dose of a medical solution, such as an insulin syringe. When a prefilled syringe in which a medical solution is prefilled is provided using a syringe of this type, the tip of the needle needs to be sealed. Such a seal cap for sealing the tip of a needle is proposed, for example, in JP 2010-534546 A (“JP '546”), and U.S. Pat. No. 6,719,732 B2 (“U.S. Pat. No. '732”).
A seal cap (shield 10) of JP '546 is configured to cover the distal extremity of a syringe (partially shown on FIG. 2 of JP '546). The distal extremity of the syringe 3 includes a hub 2 on which a needle 6 is fixed. The shield 10 has an open proximal end 11, a closed distal end 12, and a wall 13 extending from the proximal end 11 to the closed distal end 12. The internal face 14 of the wall 13 defines a cavity 15 for receiving the part of the distal extremity of the syringe 3. A portion 14a of the internal face 14 is configured to be in contact with the hub 2 of the distal extremity of the syringe 3 when the shield 10 is secured on the distal end extremity of the syringe in order to protect the distal extremity, for example during transport of an administration device before use.
On FIG. 3 of JP '546, the portion 14a of the internal face 14 of the wall 13 includes a plurality of grooves 16. The grooves 16 are regularly disposed along the circumference of the portion 14a, they are parallel to the longitudinal axes A of the shield 10. They allow air to flow during the assembly of the shield on the hub 2. The sticky surface of the shield is smaller, so the assembly is facilitated, and it is easy to have the respective longitudinal axis A and B (see FIG. 2) of both the shield 10 and the administration device 3 to remain confounded. The shield 10 of the invention is therefore perfectly and accurately secured on the extremity of the administration device 3. Because of the grooves created by the specific roughness of the portion 14a of the internal face 14 of the wall 13, it is then easier to remove the shield 10 from the extremity of the administration device 3 at the time of use of the administration device 3.
A seal cap (a device for protecting the needle of a syringe) of U.S. Pat. No. '732 is an elastic needle cap 20 extending in a longitudinal direction between an open proximal end 22 and a closed distal end 24, as illustrated in FIGS. 1 to 5. The cap 20 has an inner housing 26 delimited by a lateral wall 28 and by an end wall 30. Further, between a first and second portions 40 and 42 of the housing 26, there is provided an annular bead 70 (rib) forming an inner swell at the end of the second portion 42 facing the proximal end 22. In order to improve the deformability of this annular bead 70 and to facilitate the passage of the water vapor under pressure, the annular bead 70 is provided with four slots 72 extending in longitudinal direction.
In JP '546, the internal face of the opening of the seal cap (shield 10) has the plurality of grooves axially extending, and the seal cap is readily mounted to and removed from a barrel. However, since the seal cap is readily removed, when the barrel or the prefilled syringe to which the shield 10 is mounted is manufactured, and when the barrel or the prefilled syringe to which the shield 10 is mounted is transported, the shield 10 is likely to be removed unexpectedly from the barrel. Further, the internal face of the shield 10 is in direct close contact with an external face of a distal end of the barrel, therefore, when the barrel is stored while the shield 10 is mounted on the barrel, the shield 10 may stick to the barrel. Further, when sterilization bringing about a pressure load, such as high-pressure steam sterilization or ethylene oxide gas sterilization, is performed, the shield 10 is pressed against the barrel, so that an area of direct close contact between the internal face of the shield 10 and the external face of the distal end of the barrel is increased, and the shield 10 may be stick to the barrel.
In U.S. Pat. No. '732, the seal cap (elastic needle cap 20) has an inner face including the annular bead 70 (rib) forming an inner swell, and the bead 70 is provided with the four slots 72 extending in the longitudinal direction. Therefore, when a barrel or a prefilled syringe to which the elastic needle cap 20 is mounted is manufactured, and when the barrel or prefilled syringe to which the elastic needle cap 20 is mounted is transferred, unexpected removal of the elastic needle cap 20 from the barrel is unlikely to happen. However, the inner face of the elastic needle cap 20 has a large number of portions making a direct close contact with the outer face of the distal end of the barrel, so that when the barrel is stored while the elastic needle cap 20 is mounted to the barrel, the elastic needle cap 20 may stick to the barrel. Further, when the sterilization bringing about a pressure load, such as high-pressure steam sterilization or ethylene oxide gas sterilization, is performed, the elastic needle cap 20 is pressed against the barrel, so that an area of direct close contact between the inner face of the elastic needle cap 20 and the outer face of the distal end of the barrel is increased, and the elastic needle cap 20 may stick to the barrel.